Multistage mixing apparatus



J y 1930- H s. BEERS 35.

MULTISTAGE MIXING APPARATUS Filed April 13, 1929 2 Shaets-Sheet l I A RNEY S VEN OR Patented July 1,1930

Application filed April 13,

My invention relates to mixing apparatus, and its principal object is to provide novel apparatus for general mixing, blending or dissolving operations, and including in the mixer proper a plurality of stages; that is, two or more sets of moving blades cooperatin g with two or more sets of stationary blades, whereby the circulated material is repeatedly impelled, deflected, reimpelled and redeflect-. ed in an advantageous manner, as detailed hereafter.

The general principle of multi-stage mixing is applicable to a wide variety of mixing apparatus. In the present embodiment it is incorporated in apparatus of the turbotype, including an impeller having two spaced anthose of the im- A further object is to increase the etficiency of the mixing apparatus in operation upon mixtures including solids, fibrous material, viscous ingredients, etc., by providing grating teeth or analogous devices at favorable locations in the mixer (as more particularly referred to hereafter).

The characteristics and advantages of the invention are further so in connection with the following detail description of the accompanying drawings, which show one representative embodiment. After considering this example, skilled persons will understand that many variations may be made without departing from the principles disclosed and I contemplate the embodiment of any structures that are properly within the scope of the appended claims.

In the drawings:

Fig. 1 is a view mainly in vertical section, of mixing apparatus embodying the invention in one form.

enlarged fragmentary section at Fig. 2 is an 2-2, Fig. 1.

Fig. 3 is a section at 3-3, Fig 2. Fig. 4 is an enlarged section at 44, Fig. 2.

Fig. 5 is a section at 5-5, Fig. 2. \Vhile in one preferred form chosen for illustraiion, the mixer proper is located at the being b fiiciently explained upward position in the tank, duplex type, designed to circulate material in two general courses or directions, as will be understood b skilled persons after considering the following description. In Fig. 1 the mixer 1 is located adjacent the bottom of an ordinary or suitable tank 2 havng abottom wall 3. he mixer includes an Impeller or rotor 4 and a stationary deflector 5. In the present instance the deflector structor may be connected as an operative unit by a plate or other structure.

The impeller 4 includes an annular plate 6 having an up-curved central portion or flange forming an intake or throat and connected to the supporting and propelling shaft 8 by arms 9 engaging in a hub 10 which is secured to the shaft end as by a nut 11, or otherwise". Desirably, the arms 9 are formed as blades which produce a desired centripetal flow of material through the intake passage to the main propelling or impelling blades.

hese impelling blades are arranged in two series. Thus there is an inner series of blades 12 projecting downward from the inner portion of plate 6, and an outer series of blades 13 projecting downward from the outer portion of the plate. The blades in each series are properlyspaced, curved and approximately tangentially arranged to produce a charge of liquid.

The deflector 5 includes an inner series of blades 14 located between the impeller blades 12-43, and an outer series of blades 15 located about the outer impeller blades 13. The blades l4-15 constituting each annular series of deflector blades, are properly spaced, curved andapproximately tangentially arranged as shown in Fig. 2, to receive material discharged tangentiallyfrom one set of imblades 15 may 2 peller blades and deflect it to approximately radial flow. While as above indicated the deflector structure may in some instances be arranged as an operative unit, in the present instance the inner blades 14 are connected to or formed integrally with continuous or segmental plates 16 secured to the tank bottom 3 by welding, bolts or otherwise; and the outer blades 15 are connected to or formed integrally with webs or connecting plates 17 -18, (Figs. 3, 4 and 5). The connecting webs or plates may be arranged as a complete annulus, or may be segmental so that the complete outer deflector structure may consist of a series of arcuate segments. The ring or ring segments are secured to the tank bottom in any suitable way as by bolts 19. In the form 0 outer deflect r here shown ortions 15 located below the connecting or intermediate plates or webs 17-18, and other portions 15 extending upward from such plates or webs; otherwise in some cases the simply project up from the tank bottom or down from a connecting continuous or segmentary annular plate, with omission of the upper portions 15".

Preferably, as in the present example, alternate connecting plates or webs 17--18 are differently located or arranged; thus, the plates 17 are desirably approximately horizontal or parallel to the tank bottom, and the other intermediately located plates 18 are curved and inclined more or less sharply outwardly upward, as clearly shown in Fig. 5, thus'providing for the discharge ofa part of the material, under the control of plates 1'? along the tank bottom and toward the lower corner of the tank, and other portions under the control of plates 18 in a more abruptly upward direction and toward at the surface level, thus avoiding undesired dead spots and insuring adesired complete circulation of the material.

In operation, material entering the impeller intake or throat 7, is discharged outwardly and tangentially by blades 12 and is received by the inner deflector blades 14 which divert the flow to generally radial directions; the

material is then encountered by the outer 1m-' eller blades 13 and again propelled outwardy and tangentially, and is received by the outer deflector blades 15 and again diverted to substantially radial flow. I thus provide repeated diversions of the liquid flow and repeated beating actions, so that the mixing, blending or dissolving action, reduction and intermixing of solids, etc., are greatly expedited and the general efficiency of apparatus greatly increased in comparison with the t y pical single stage mixer including only one set of propelling blades and one set of stationary or deflecting blades.-

I also desirably provide additional means for breaking down. grating or otherwise reducing solids or viscous components of the the tank wall mix, such means consisting of blade or tooth formations at desirable locations in the mixer. Thus I provide grating teeth 20 on the anterior faces of deflector blades 14-45, that is the faces which are directly encountered by the material tangentially discharged from the impeller blades. \Vhile similar teeth may in some cases be located on the rear or posterior faces of the deflector blades, such teeth are relatively ineffective and may generally be omitted. The teeth are desirably formed by gouging or punching operations and may thus be integral with the blades, being pressed or gouged-up therefrom. There is preferably a multiplicity of the teeth on each blade face, arranged in rows and in staggered relation in f adjacent rows. 4 the blades 15 have Similar grating teeth 21 may also when desired be provided on either or both the upper andlower faces of the connecting plates or webs17-18 of the outer deflector structure, or any of such )lates. In operation, the circulated material moves rapidly over the serrated or toothed faces of blades 1415 and plates 17-18, and solid or vitreous lumps 0r masses and viscous or analogous components are thus subjected to repeated tearing action by the teeth, and are quickly broken down or separated and intermixed or dispersed throughout the liquid body, this action being much more efficient and rapid in the case of materials of the character indicated than when the grating teeth are omitted. I preferably do not provide the grating teeth on the blades of the impeller, since teeth insuch locations will generally tend to retard the flow of liquid, and it is desired to maintain the efiiciency of the impeller action in order to keep up the desired rapid circulation and avoid increase in power con sumption, etc. The grating teeth located on stationary members such as the. deflector blades and connecting plates or webs do not impede material flow to an undesirable extent or objectionably increase power consumption.

I claim:

1. A- mixer comprising a rotor having a plurality of annular series of material impelling blades, and a plurality of annular series ofstationary curved angular deflector blades radially interspaced with the impelling blades, the impelling blades being curved and approximately tangentially arranged for tangential material discharge an the deflector blades being curved and approximately tangentially arranged in reversed relation to the arrangement of the impeller blades, for radial deflection and discharge of the material.

2. Mixing apparatus comprising a rotary impeller including connecting means, and thereon a plurality of radially spaced annular series of impelling blades, and deflecting means comprising a plurality of radially Ill) spaced annular series of deflecting blades. the deflecting blades being radially interspaced with the impelling blades, the blades being curved in cross-axial planes and angular to axial planes, the curvature and angularity of the impelling and deflecting blades being relatively opposite. 3

3. Mixing apparatus for relatively rapid and continuous circuitous movement and mixing of materials of a generally liquid character, comprising a rotor, blades thereon arranged in a plurality of spaced annular series. the blades in each series being spaced, curved and angularly arranged in relation to axial planes providing for turbo-impeller action and tangential discharge of material, and a stator including a plurality of annular series of deflector blades. said series being interspaced with the series of impeller blades, and the deflectbr blades in each series being spaced. curved, and aranged at angles to axial planes to discharge material substantially radially.

4. Mixing apparatus for relatively rapid and continuous circuitous movement and mixing of materialsot a generally liquid character. comprising a rotor, blades thereon arranged in a plurality of spaced annular series. the blades in each series being spaced. curved and angular-1v arranged in relation to axial planes providing for turbo-impeller action and tangential discharge of material. and a stator including a plurality of annular series of deflector blades. said series being interspaced with the series of impeller blades. and

the deflector blades in each series being series. the blades in each series being spaced curved and angularly arranged in relation to axial planes providing for turbo-impeller action and tangential discharge of material, and a stator'including a plurality of annular series of deflector blades, said series being interspaced with the series of impeller blades, and the deflector blades in each series being spaced, curved, and arranged at angles to axial planes to discharge material substantially radially, edges of the rotor and stator blades being approximately adjacent and producing repeated shearing actions on solid or semi-solid components of the material.

1 6. Mixing apparatus for relatively rapid and continuous circuitous movement and mixing of materials of a generally liquid character, comprising a rotor including an annular plate having an entrance throat and providing a flowdefining and directing wall in cooperation with another wall, said walls defining an annular flow space approximate- 1y uniform area from the throat to the discharge annulus, a plurality of series of curved, angular impelling blades on said plate, and a plurality of series of curved, angular stationary deflector blades, the series of deflector blades being interspaced with those of impelling blades and producing turbo-flow of material at substantially uniform rate from inside to outside with repeated changes of flow direction.

7. Mixing apparatus comprising relatively moving and stationary curved angular blades arrangedin a plurality of series for multistage action upon circulated material, certain of the blades being provided With a multiplicity of grating teeth.

8. Mixing apparatus comprising a plurali-ty of annular series of spaced curvedangular rotary impeller blades and interispaced annularseries of stationary curved angular deflector blades for multi-stage impulsion and diversion of circulated material, certain of the deflector blades being provided witli a multiplicity of grating teeth.

9. A mixer comprising a rotor having a plurality of annular series of curved angular material impelling blades, and a plurality of annular series of stationary curved angular deflector blades radially interspaced with the impelling blades, anterior faces of certain of the deflector blades being provided with multiplicity of grating teeth.

10. Mixing apparatus comprising a plurality of annular series of spaced curved angular rotary impeller blades and interspaced annular series of stationary curved angular deflector blades for multi-stage impulsion and diversion of circulated material, an outer series of said deflector blades having interspaced therewith approximately horizontal flow-controlling plates, certain faces of certain of said plates being provided with a multiplicity of grating teeth.

11. Mixing apparatus comprising relatively moving and stationary curved angular blades arranged in a plurality of series for multi-stage action upon circulated material, certain of the stationary blades being provided with a multiplicity of grating teeth, said teeth being formed integrally in the material of the blades.

' 1.2. Mixing apparatus comprising a plurality of annular series ofspaced curved angular rotary impeller blades and interspaced annular series of stationary curved angular deflector blades for multi-st-age impulsion and diversion of circulated material,

an outer series of said deflector blades having interspaced therewith approximately horizontal flow-controlling lates, certain faces of certain of said plates ing provided with ,5 a multiplicit of grating teeth, said teeth being forme integrally in the material of the plates.

13, Mixing apparatus for relatively rapid and continuous circuitous movement and 10 mixing of materials of a generally liquid character,'comprising a rotor, blades thereon arranged in a plurality of spaced annular series, the blades in each series being spaced, curved and angularly arranged in relation to axial planes providing for turboimpeller action and tangential discharge of material, and a stator including a plurality of annular series of deflector blades, said series being interspaced with the series of 29 im ller blades, and the deflector blades in eac series being spaced, curved, and arranged at angles to axial planes to discharge material substantially radially, the outer series of deflector blades having interspaced g5 therewith relatively horizontal plates arranged to direct material flow in axial planes. In testimony whereof I afiix my signature.

HENRY SANFORD BEERS.

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